In a speech to rights activists, educators and students from more than 20 countries, Clinton said growing protests around the Mideast show the need for them to organize and present demands to governments.
The top U.S. diplomat said the United States will back any peaceful effort for greater political, economic and social openness in repressive societies and appealed for governments to embrace civic leaders rather than treating them as enemies.
"If we are going to take advantage of this historic moment, we have to tap the expertise, experience and energy of civil society," Clinton said. "Across the Middle East today we see people calling on governments to be more open, more accountable, more responsive. People want a stronger voice in their own affairs."
"It is in the interests of governments to answer these demands, to reflect the will of their own people," she said.
She also said the U.S. will boost contributions to an emergency fund to help detained activists.
Her comments came as anti-government demonstrations inspired by Egypt and Tunisia spread to other countries in the region, including Iran, Jordan, Yemen, Syria and Bahrain.
"None of us can ever predict what will spark the kind of movements we have seen," she said. "But we know that the power of human dignity is always underestimated until the day it finally prevails."